1. Field of the Invention
The present invention relates to photographic apparatus in general and to reflex cameras in particular.
2. Description of the Prior Art
Reflex cameras, particularly of the 35 mm type, are, of course, well known owing to their popularity among photographers, professional and amateur alike. Their popularity is based to some extent on the fact that they permit the use of interchangeable lenses of different parameters without requiring viewfinders specific to each lens or provided with frames delineating the field of view of a particular lens. Such cameras make use of a reflector intercepting the optical path of the objective lens for reflecting a true image of the scene to be photographed into the viewfinder. For subsequent exposure of film, the reflector is moved out of the optical path.
In some instances, reflex cameras may use a reflector for directing the image not only into the viewfinder but also to the film for exposure purposes.
The present invention relates to this latter type of reflex camera and will be described, by way of example, as incorporated in a copy camera. Those skilled in the art will appreciate, however, that the inventive concept may be applied to photographic cameras generally.
Copy cameras as exemplified by the multi-purpose industrial view camera marketed by Polaroid Corporation of Cambridge, Mass., under its registered trademark MP-4, comprise a normally open shutter, an objective lens, and a viewing and focusing screen for rendering an object to be photographed visible to an operator. Visibility of the object is enhanced by a hood covering the screen and an eyeshade as well as a reflex member within the hood for deflecting an image of the object towards the eyeshade. Having framed and focused the image, an operator may proceed to taking a photograph thereof. This may be done in one of two possible ways: the operator may insert a film unit under the viewing screen. The film unit, for this purpose, is first inserted into a holder and is provided with a dark slide. Insertion of the film holder into the camera results in automatic closure of the shutter. Once the holder is properly positioned within the camera, the operator removes the dark slide from the film and exposes the film by actuating the previously set shutter. Thereafter, the film unit is again covered by the dark slide and processed in a well-known manner.
The other way of exposing a film unit with the copy camera referred to is laterally to move the screen out of the path of the optical axis and to move a magazine of film units into the position until then occupied by the viewing and focusing screen, after framing and focusing the scene or object has been completed. This movement leads to closing of the shutter to prevent the film unit located in the magazine for exposure from being exposed accidentally. Once the film unit is in its exposure position, a dark slide is removed from it, and the shutter is then actuated for exposure. Thereafter, the film unit is removed from the magazine and processed in a well-known manner. Before returning the magazine to its original position, the film units remaining therein have again to be covered by the dark slide lest they be spoiled by light.
It will be apparent to those skilled in the art that the sequential uncovering and covering of film units by a dark slide requires relatively complex manipulations and may, if not properly attended to, lead to spoiling of film within the magazine.